Effectiveness of Topical NSAIDs in Osteoarthritis Limited to 2 Weeks

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Effectiveness of Topical NSAIDs in Osteoarthritis Limited to 2 Weeks

Yael Waknine

Aug. 1, 2004 ‹ Topical nonsteroidal anti-inflammatory drug (NSAID) use in

osteoarthritis is only effective during the first two weeks of treatment and

is comparable to placebo at one month, according to the results of a

meta-analysis of 13 randomized controlled trials published in the British

Medical Journal Online First July 30 issue.

" NSAIDs have been applied topically for decades, " writes Jinying Lin, MD,

from the People's Hospital of Guangxi Province in the People's Republic of

China, and colleagues. " This route possibly reduces gastrointestinal adverse

reactions by maximizing local delivery and minimizing systemic toxicity. "

They continue, " A systematic review in 1998 confirmed that topical NSAIDs

were superior to placebo over two weeks in the treatment of chronic pain,

including osteoarthritis and tendonitis, " adding that outcomes of stiffness

and function were not addressed, studies pooled were not limited to

osteoarthritis, and no study was longer than two weeks.

To determine the efficacy of topical NSAIDs compared with placebo and oral

NSAIDs over a longer period of time (four weeks), investigators performed a

meta-analysis of 13 randomized controlled trials involving 1,983 patients

diagnosed specifically with osteoarthritis.

Topical NSAIDs were found to be more effective than placebo in alleviating

osteoarthritic pain only over the first week (effect size, 0.41; 95%

confidence interval [CI], 0.16 - 0.66) and second week (effect size, 0.40;

95% CI, 0.15 - 0.65) of treatment. Topical NSAIDs did not show any benefit

over placebo in weeks 3 or 4. Trends for function, stiffness, and clinical

response rate ratio and number needed to treat showed similar patterns.

Topical NSAIDs were significantly less effective than oral NSAIDs in

reducing osteoarthritic pain during the first week, and numerically so in

other weeks. Topical NSAIDs were associated with more local adverse effects

including rash, itch, and burning sensations (rate ratio, 5.29; 95% CI, 1.14

- 24.51).

" Most randomized controlled trials of treatment for osteoarthritis last only

two weeks, and no trials go beyond four weeks, " the authors write.

" Meta-analysis of this limited data shows that treatment of osteoarthritis

with topical NSAIDs is only beneficial in the first two weeks and at one

month is comparable to placebo. Research evidence to support the long term

use (more than one month) of topical NSAIDs in osteoarthritis is absent. "

Limitations of the study include language bias, the number of trials

available for pooling, and differences in efficacy of the various NSAIDs

studied.

" Our meta-analysis challenges current guidelines from Europe and America

that topical NSAIDs are an effective treatment for osteoarthritis of the

knee, " the authors point out. " Current recommendations that support their

use in osteoarthritis need to be revised. "

This study was funded by grants from the U.K. Arthritis Research Campaign.

BMJ. Posted online July 30, 2004.

Reviewed by D. Vogin, MD